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ZX Spectrum Next

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ZX Spectrum Next
A cased ZX Spectrum Next from the 1st Kickstarter
ManufacturerSMS Electronics
TypeHome computer
Release date
  • 1st Kickstarter: December 2017 (development board), February 2020 (cased)
  • 2nd Kickstarter: December 2023
Units sold
  • 1st Kickstarter: 3010+ (3010 cased)
  • 2nd Kickstarter: 5100+
CPUZilog Z80 implemented in FPGA
  • 1st Kickstarter: 1024 KiB (upgradeable to 2048 KiB)
  • 2nd Kickstarter: 2048 KiB

ZX Spectrum Next is an 8-bit home computer, initially released in 2017, which is compatible with software and hardware for the 1982 ZX Spectrum. It also has enhanced capabilities.[1][2] It is intended to appeal to retrocomputing enthusiasts and to "encourage a new generation of bedroom coders", according to project member Jim Bagley.[3]

Despite the name, the machine is not directly affiliated with Sinclair Research Ltd., Sir Clive Sinclair or the current owner of the trademarks, Sky Group.


The Next started life in 2010 in Brazil, as a variant of the TK95 Spectrum clone. In 2016, Victor Trucco and Fabio Belavenuto announced the "TBBlue" firmware, named after the two creators and the colour of the solder mask of the motherboard, a bare circuit board implementation of the product for advanced hobbyists.

With the help of Henrique Olifiers the duo wanted to export the TBBlue to the UK, the ZX Spectrum's original home, having received moderate success with the board in Brazil.[4]

The Next was first announced as a distinct product in 2016 after the participation of original Spectrum industrial designer Rick Dickinson was secured. A crowdfunding campaign was launched on the Kickstarter platform in January 2017 with an initial funding goal of £250,000.[5] At the end of the campaign 3,113 backers pledged £723,390. While the campaign was successful in creating a userbase for the new platform, it was not a commercial success. Due to what campaign creators call "bad tax advice" the production of the machines ended up causing costs instead of revenue to the creators.[6]

Although initially intended to use the original ZX Spectrum's Z80 chip,[7] the design was altered to use the Xilinx Spartan-6 FPGA,[8] to allow "hardware sprites, scrolling, and other advanced features to be incorporated within the machine itself".[3]

The board-only computer was delivered to backers in December 2017.[9] After some design and production delays, the first batch of finished units were delivered to backers in March 2020.

A second Kickstarter launched on 11 August 2020 at 21:00 BST and reached 100% funding (£250,000) within minutes.[10][6][11] The campaign closed on 10 September 2020 with £1,847,106 (738% funding)[12]

Industrial design[edit]

The Next's case design[13] is by Rick Dickinson who designed the original 48K Spectrum and Spectrum+, but passed away during the development of the keyboard of the computer.[14] It takes design cues from the Spectrum+ and Spectrum 128, not the later Spectrum +2 or +3 manufactured by Amstrad.


The Next has received generally favorable reviews in the specialist press. In the official Raspberry Pi magazine "MagPi", Lucy Hattersley called it "a lovely piece of kit", noting that it is "well-designed and well-built: authentic to the original, and with technology that nods to the past while remaining functional and relevant in the modern age".[8]

In PC Pro magazine, columnist Gareth Halfacree called the Next "undeniably impressive" while noting that the printed manual lacks an index, and that some features are "not quite ready".[15]

Retro Gamer featured an 8-page interview with the creators of the machine about the highs and lows of creating a "true successor to the much-loved Sinclair micro".[4]


Revisions of the Next's motherboard's design are referred to as "Issues", in keeping with the original ZX Spectrum,[16] and have been made to either improve quality or in response to problems with the supply of components. Care has been taken to not change the core capabilities, compatibility, and specifications of all models of the Next between Issues.

Overview of the Next hardware specifications
Aspect Details
CPU Z80N (Zilog Z80 compatible with additional instructions) implemented in FPGA
Speed 3.5, 7, 14 or 28 MHz
RAM 1024 KiB base (768 KiB free), 2048 KiB maximum (1792 KiB free), in 8 KiB banks paged in and out of Z80's 64 KiB address space; 256 KiB is reserved for ROMs
Graphics From 128 × 96 to 640 × 256 pixels.
Colour Depending on mode and layer, 16 or 256 colours on-screen with no colour clash in certain modes, from a palette of 512 colours.
Sprites Up to 128 hardware sprites of 16 × 16 pixels
Sound Traditional "Beeper", 3 × General Instrument AY-3-8910 programmable sound generators (each with 3 channels for a total of 9 channels), and 4 × 8-bit DACs implemented in FPGA
Software NextZXOS Operating System + NextBASIC; prior versions of Sinclair BASIC and optionally CP/M
Connectivity Tape in/out, Audio out, HDMI, VGA/RGB, 2 x Cursor/Kempston/Sinclair joystick connectors, PS/2 mouse port (Kempston mouse emulation), ZX Spectrum compatible expansion bus, WiFi on selected models
Storage Built-in DivMMC compatible SD-card slot; optionally cassette tape, Sinclair ZX Microdrive (with Sinclair ZX Interface 1) or any other storage system compatible with original ZX Spectrum series

First Kickstarter[edit]

Four models of the Next were produced in the first Kickstarter[citation needed] using the Xilinx Spartan-6 FPGA[citation needed].

Overview of the first Kickstarter's Next models
Model name Cased real-time clock installed Wi-Fi installed Raspberry Pi Zero "Accelerator" installed Board Issue Notes
ZX Spectrum Next developer board No No No No 2A Only board Issue which can fit in an original, modified, ZX Spectrum case
ZX Spectrum Next Yes No No No 2B Does not require modification, with a capacitor, to eliminate electronic "noise"[17]
ZX Spectrum Next Plus Yes Yes Yes No 2B
ZX Spectrum Next Accelerated Yes Yes Yes Yes 2B Accelerator enables loading compressed tzx tape images from SD-card and provides emulation of the MOS Technology 6581 SID soundchip.

All models include 1024 KiB RAM (768 KiB free) and can be upgraded by the owner;

  • Adding two 512 KiB chips brings the RAM to 2048 KiB (1792 KiB free).
  • An internal "beeper" speaker can be installed.
  • Any of the higher models' optional extras can be installed.

Second Kickstarter[edit]

Two models of the Next were offered in the second Kickstarter[citation needed][18] using the Xilinx Artix-7 FPGA[citation needed].

Overview of the second Kickstarter's Next models
Model name Raspberry Pi Zero "Accelerator" installed Notes
ZX Spectrum Next Plus No Wi-Fi module relocated to avoid audio interference
ZX Spectrum Next Accelerated Yes

Both models are cased, include a real-time clock, Wi-Fi, and 2048 KiB RAM (1792 KiB free), use board Issue 4, and can be upgraded by the owner;

  • An internal "beeper" speaker can be installed.
  • A Raspberry Pi Zero unit can be installed as an "Accelerator" into the Next Plus.

Operating system and software[edit]

The default operating system of the Next is NextZXOS. The operating system provides a graphical file browser and menu based access to Next's features. In addition the machine has an extended BASIC interpreter NextBASIC, with commands and features added to support the new capabilities, such as support for 9-channel AY-sound and built-in sprite graphics editor.

NextZXOS and NextBASIC were written by Garry Lancaster, and the machine is provided with printed manual covering the OS and BASIC in detail. The first edition of the manual can be downloaded from the official website.

In addition to the native OS, the Next is able to run prior versions of Sinclair BASIC, such as 48K BASIC and 128K BASIC. The Next is also able to run CP/M. Although this does potentially open a sizeable software library of CP/M to the Next users, it is worth noting that CP/M cannot take advantage of the machine's advanced capabilities, such as large memory.

Some 3rd party "Next only" software has sprung into existence despite the comparatively short time that the machine has been on the market.[19] These include the likes of NxTel by Robin Verhagen-Guest (a Teletext-style Next specific webservice accessible via Wi-Fi), and NextDAW by Gari Biasillo (a digital audio workstation software capable of utilizing the Next's sound capabilities for creating Chiptunes). NxTel comes bundled with the machine on the accompanying SD-Card.

Some of the original ZX Spectrum games have also been upgraded or are being upgraded to utilize Next's improved graphics and sound. Among the most notable remakes are Atic Atac with improved graphics by Craig Stevenson. The new game version is backed by the current owner of the rights Rare studio and the Next port is written by Kev Brady.[20]


The NextZXOS and NextBASIC are both released under Open/Closed-Source hybrid license called "The Next License", with all parts of the OS being closed source by default, unless explicitly placed under Open Source MIT License. The Next License prohibits selling the software and charging a duplication fee for it, but cost-free distribution is allowed under the CreativeCommons Attribution-ShareAlike license. The OS and BASIC are publicly hosted on GitLab.

Hardware is released under a "mixed source" proprietary license. The VHDL/Verilog for the FPGA digital design is available on GitLab and licensed under GPL3. Everything else is closed including the Schematics, the PCB master files and keyboard/case 3D model.

Personalities and alternative FPGA cores[edit]

The Next is able to reproduce the behaviour of any prior Sinclair ZX80, ZX81 or Spectrum machine, as well as some notable ZX Spectrum clones (both official and unlicensed) through a feature called "Personalities". Examples of such clone personalities are Timex Sinclair TC2048 and the Russian Pentagon machines. Personalities can match hardware features, timings, memory, graphics and sound capabilities and OS version with the machines to be reproduced in an effort to provide full compatibility with them. The default personality of the Next is based on Sinclair ZX Spectrum +3e. It is also possible for the user to configure and add new personalities as needed.[citation needed]

The Next can also be used to recreate a number of other, non-Spectrum based computers, such as the Acorn BBC Micro, as long as their hardware will "fit" into the FPGA.[21] These recreations are known as "cores". The machine can also be made to boot directly into an alternative core. While the use of alternate cores is supported, the cores themselves are unofficial third-party projects. A Sinclair QL core is described as "very stable, [ booting ] every time".[22]

Clones and emulators[edit]

An N-GO board, a clone of ZX Spectrum Next

The Next team actively encourages the manufacture of clone machines to promote and expand the userbase as much as possible.

Clones of the Next include:[citation needed]

Xilinx FPGA based-clones
  • ZXDOS+ (board) / gomaDOS+ (board with case)
  • N-GO (board/computer), which can be installed into a (modified) ZX Spectrum case in the same way as the Next Issue 2A or comes with its own mechanical keyboard+enclosure
  • XBerry Pi, a Raspberry Pi sized miniaturized full ZX Spectrum Next clone[23]
Altera FPGA-based clones
  • UnAmiga (board with case)
  • UnAmiga Reloaded (board with case)
  • Multicore 2 / Multicore 2+ (board with case)
  • NeptUNO (board with case)
  • MiST (Core with TZX loading and RTC support)
  • Sidi (Low cost MiST derivative)
  • Mister (Core with special dual SDRAM/SRAM memory addon)
  • MiSTer an Intel Cyclone V based board with 1 GB DDR3 and hundred opensource retro cores [1]

Emulators of the Next include:[24]

  • ZEsarUX by Cesar Hernandez[25]
  • #CSpect by Mike Dailly[26]


  1. ^ Bush, Steve (April 28, 2017). "ZX Spectrum rides again, with Z80 and optional Raspberry Pi Zero". Electronics Weekly.
  2. ^ Beschizza, Rob (April 30, 2017). "ZX Spectrum Next is an advanced version of the original 8-bit monster machine". BoingBoing.
  3. ^ a b Crooks, David (December 2019). "ZX Spectrum Next Raspberry Pi project showcase". MagPi Magazine.
  4. ^ a b Carroll, Martyn (January 15, 2020). "The Next Level - Introducing the ZX Spectrum Next". Retro Gamer (UK).
  5. ^ "Celebrate the Sinclair ZX Spectrum's 35th anniversary with… yet another retro console". Metro (UK). April 24, 2017.
  6. ^ a b "ZX Spectrum reboot promising – steady now – 28MHz of sizzling Speccy speed now boasts improved Wi-Fi". The Register. August 13, 2020.
  7. ^ Ridden, Paul (April 24, 2017). "Home computing classic reborn as ZX Spectrum Next". New Atlas. Retrieved August 13, 2020.
  8. ^ a b Hattersley, Lucy (April 2020). "ZX Spectrum Next Accelerated review". MagPi Magazine.
  9. ^ "Update 24: What's next for the Next (including full computers shipping estimate) · ZX Spectrum Next". Kickstarter. Retrieved August 13, 2019.
  10. ^ "Opvolger ZX Spectrum Next krijgt snellere cpu-modes en meer ram". Tweakers. August 12, 2020.
  11. ^ "ZX Spectrum Next Issue 2 blasts through Kickstarter goal". BBC News. August 13, 2020. Retrieved August 13, 2020.
  12. ^ Clark, Adam. "Kicktraq: ZX Spectrum Next - Issue 2". Kicktraq. Retrieved September 7, 2021.
  13. ^ "Specnext1.1157". September 28, 2017.
  14. ^ Halfacree, Gareth (April 26, 2018). "Industrial designer Rick Dickinson passes away". Bit-Tech.Net.
  15. ^ Halfacree, Gareth (July 2020). "ZX Spectrum Next". PC Pro Magazine (UK). No. 309. pp. 48–50.
  16. ^ "ZX Spectrum Models". Spectrum For Everyone. Retrieved April 25, 2022.
  17. ^ Olifiers, Henrique. "Next Board 2A Capacitor Mod". ZX Spectrum Next. Retrieved August 13, 2020.
  18. ^ "ZX Spectrum Next Second Kickstarter smashes its goal in less than fifteen minutes! | News | The Digital Fix". Gaming @ The Digital Fix. August 11, 2020. Retrieved August 21, 2020.
  19. ^ "Games". Spectrum Next Games. Retrieved August 20, 2020.
  20. ^ "Melkhior's Mansion - In Dev Ultimate Play the Game Atic Atac inspiration looks so awesome!", Indie Retro News, August 17, 2020
  21. ^ Dokos, Phoebus (April 27, 2020). "Multiple FPGA Cores Support". ZX Spectrum Next. Retrieved August 13, 2020.
  22. ^ Trucco, Victor. "QL progress #1". Patreon. Retrieved August 25, 2020.
  23. ^ "Xberry Pi". ZX Renew. Retrieved February 11, 2024.
  24. ^ "Emulators". SpecNext official Wiki. Retrieved August 14, 2020.
  25. ^ Olifiers, Henrique. "ZEsarUX: Next emulator". ZX Spectrum Next. Retrieved August 14, 2020.
  26. ^ Dailly, Mike. "#CSpect V2.12.34". The life of a Games Programmer. Retrieved August 14, 2020.

External links[edit]